Greenland Expedition Explores Impacts of Rapid Change

Greenland Expedition Explores Impacts of Rapid Change

Eighty percent of Greenland - an area about three times the size of Texas - is covered by a sheet of ice. Upwards of two miles thick, that ice is constantly moving, flowing downhill like a river toward the ocean through impressive glacial fjords. The margins of the ice sheet, where it meets the cold waters of the Arctic and Atlantic oceans, are home to productive ecosystems that support an abundant array of marine life and thriving coastal communities.

A team of American and Greenlandic scholars, featuring researchers from Bigelow Laboratory for Ocean Sciences, is working to understand the natural and human dimensions of those marine glaciers and how they're changing. Funded by the National Science Foundation Navigating the New Arctic program, the team has undertaken several expeditions, most recently this August, to collect a suite of physical, chemical, and biological data from several fjords around Greenland.

"As Greenland changes, you have seawater coming into the fjord mixing and interacting with all the freshwater running off the glaciers," said Paty Matrai, a senior research scientist emerita involved in the project. "Our goal is to understand what those physical changes are doing to these marine ecosystems and how that might influence local communities that depend on these coastal resources."

Rising water temperatures and sea ice melt are reshaping the confluence of physical forces that act on Greenland's tidewater glaciers, which has cascading impacts on the entire system. Phytoplankton, for example, bloom earlier and longer in warmer, ice-free areas. That, in turn, changes the movement of carbon and nutrients through the water column.

Led by Fiamma Straneo, now a professor at Harvard University, the team of researchers came together to unravel this web of environmental interactions - and better understand what challenges and opportunities these changes might present for people living there.

Matrai became involved in the project through Mattias Cape, now a scientist for the Environmental Defense Fund and an adjunct researcher at Bigelow Laboratory. They met when he was analyzing some of the samples from his PhD research at Bigelow Laboratory, leveraging the technical capabilities of Matrai's lab. Together, they bring valuable biogeochemistry expertise to the project.

This August's expedition was the fourth and final cruise, sailing to Greenland's remote west coast aboard a Greenland Institute of Natural Resources vessel, the R/V Sanna.

"All four trips have been in August, on purpose," Matrai explained. "That way we can get a snapshot at almost the same time, year after year, and see how the system is changing at an annual scale."

On each cruise, they're sampling across the continental shelf around several fjord systems. They are going further offshore than many local expeditions but also getting deeper into the recesses of the coast than most international projects (Matrai jokes that only ship captains from Greenland and the Faroe Islands are brave enough to sail through these ice-laden waters).

In 2023 and 2025, they sailed to Sermilik, a massive glacial fjord in southeastern Greenland. Influenced by the Atlantic Ocean, Sermilik has relatively "mild" winters and a long sea-ice-free season. In contrast, in 2024 and this year, they traveled to the northwest along Baffin Bay, an area known for long, cold winters and heavy sea ice cover. The two sampling regions represent very different oceanographic conditions, enabling the researchers to see how things are changing differently on margins influenced by the Arctic versus the Atlantic oceans.

The team has collected a range of measurements to understand how freshwater and saltwater are mixing. There are also team members looking at zooplankton, fish, and even the human communities in the area.

On the biogeochemistry side, Matrai and Cape are collecting chlorophyll and pigments while using flow cytometry to characterize smaller particles and single-cell organisms in the water. All of this information allows them to understand how many and what kinds of phytoplankton live in these fjords. The productivity of the system, in turn, has a significant impact on how nutrients like carbon cycle through the system.

One particularly exciting element of the data collection is a number of moorings the team has left out in the fjords for two years between cruises, providing a unique, multi-year time series of physical and biogeochemical information.

"Our scientific goal is to understand and quantify the interplay between glaciers and coastal oceans that creates the physical and chemical setting that allows for enhanced primary production," Matrai explained. "That interplay may result in larvae of polar cod, halibut, and other fish species growing to adult sizes that could support Greenland's thriving halibut fishery in a sustainable manner under changing conditions."

Alongside the data collection, the team has prioritized community outreach. During each cruise, they've connected with local schools, sharing scientific equipment with teachers and bringing students on board to explore the ship. They also have a graduate student involved who translates their materials into Greenlandic and have hosted two Greenlandic teachers-in-training during two of the cruises. In 2023, Matrai even brought back seaweed and sediment samples to analyze at Bigelow Laboratory to alleviate local concerns of oil contamination. These efforts to work with Greenlandic partners enhance the research and ensure it is useful and accessible to local communities.

Having recently returned from the cruise this past August 2026, Matrai noted the natural beauty, extremely harsh environment, and isolation of the small fishing communities in their study area, while Greenland, as a country, opens up to the rest of the world via tourism and mining.

"We're collecting lots of different data to really understand the base of the food chain in this rapidly changing environment," Matrai said. "It's Bigelow science at its best."

Photo Captions

Photo 1: RV Sanna with Tuttulikassaap Sermia (Hayes Glacier) in the background during the recent expedition (Credit: Aurora Roth, Harvard/SIO).

Photo 2: Senior Research Scientist Emerita Paty Matrai collects a sample in Greenland in 2023 (Credit: Alex Rivest).

Photo 3: A group of researchers including Mattias Cape (left, foreground) examine krill in 2023 (Credit: Alex Rivest).

Photo 4: A researcher prepares equipment during the 2024 research cruise along Baffin Bay (Credit: Aurora Roth, UCSD/Harvard).